What is Brick Veneer?
What is brick veneer?
And why is it laying on the ground in the featured photograph?
Brick veneer is in essence a masonry siding, which has been set separate, that is, with an air space (commonly called a cavity), from the structural back-up wall behind it (see Figure 1). The structural back-up may be concrete block, wood framing, light-gage steel framing, or other framing system.
The BRICK VENEER I am writing of is comprised of brick that are approximately four inches thick (see the featured photograph). The THIN BRICK VENEER comprised of brick or stone that are approximately ½ inches thick is another article (see What is Manufactured Stone Veneer?).
Brick veneer provides no structural strength for supporting gravity or uplift (downward and upward) loads because the weight of the building and its occupants or contents is supported on the structural back-up wall. Brick veneer provides little additional capacity for a wall to resist shear (side to side) loads commonly required for building stability because the separation prevents the transfer of the side to side loads to the brick veneer. Brick veneer provides little additional capacity for a wall to resist inward or outward wind pressures because it is usually much more flexible than the back-up wall and it relies on the structural back-up wall to resist the wind pressures.
Brick veneer is basically a pretty face that provides some resistance to water and air infiltration, but if it develops cracking even its resistance to water and air infiltration is reduced.
Wood, vinyl, or aluminum siding are usually set against and tied back to the structural back-up wall with nails. These sidings hang on the wall like a picture hung on the inside: the nails keep the siding from sliding down or being pulled off. Brick veneer usually rests on a shelf in the foundation wall or provided by a steel angle fastened back to the foundation wall or structure. The lower bricks of the veneer support the higher bricks vertically, but what holds the brick back to the structural back-up wall so that it doesn’t lean over or get pulled over by wind pressures and fall off?
The answer is “Brick ties,” sometimes called, “wall ties.” Brick ties are straps, rods, wires, etc. that are fastened to the face of the structural back-up wall and project out into the joints of the brick veneer. See the corrugated metal straps in Figure 1.
These ties basically hold the brick veneer in place, providing a lateral (horizontal) strength so that the veneer doesn’t lean inward or outward or fall off. Brick ties are commonly spaced at 16 inches on center vertically and horizontally. The reason for this spacing is mainly because this pattern matches the spacing of the horizontal joints in the brickwork and the spacing of the common wall studs and the spacing has been found to be close enough to provide adequate horizontal support against cracking.
But, why is the brick veneer in the featured photograph laying on the ground?
Stay tuned for the next technical post.